Iraqi soldiers reload a weapon during clashes with Islamic State militants on the outskirts of Makhmour, south of Mosul, Iraq, March 25, 2016. REUTERS/Azad Lashkari/File Photo

ANDREWS AIR FORCE BASE, Md.—As leaders from across the U.S.-led coalition against the Islamic State group meet in Washington this week, they are increasingly facing a crucial question: How will the coalition help the Iraqi government put the city of Mosul back together after it is taken back from the militants?

The city of some 2 million people has been the de facto capital of the Islamic State in Iraq for more than two years. Coalition-backed Iraqi troops have been fighting on Mosul’s outskirts for weeks as they seek to eventually retake it, but officials have yet to address what happens after the city is retaken — issues like how civilians will be cared for, neighborhoods will be rebuilt and improvised explosives sowed across the city will be found and rendered harmless.

Defense Secretary Ashton B. Carter said that the “biggest strategic concern” raised by defense ministers at a meeting of coalition defense ministers here Wednesday was that stabilization and efforts to bring governance to Mosul do not lag compared to the military campaign. The issue came up as Gen. Joseph L. Votel, the chief of U.S. Central Command, laid out what the next steps in the fight against will be, Carter said.

“Most of our conversation today was not, in fact, about the movements of forces, because that was planned a long time ago. And that’s going fine,” Carter said. “Most of our conversations today was…  about what happens after the defeat of ISIL in Mosul. Stabilization plans, reconstruction plans and so forth. And we’re identifying the requirements there, which are large, because as General Votel indicated, it’s a large city.”

The comments came as Secretary of State John F. Kerry joined with leaders from Canada, Germany, Japan and the Netherlands in a conference in Washington devoted to drumming up money to rebuild Iraq. Kerry said that $2 billion already has been promised, and will be put toward humanitarian aid, de-mining, immediate stabilization, and longer-term recovery.

“It is important to come in underneath the military liberation with the type of support for rebuilding, for health, for education, to be able to make sure that we’re not leaving the door open for a disgruntlement or the revisiting of Daesh that undoes the liberation itself,” Kerry said, using an alternate name for the militants.

The meetings are not without controversy, however. A decision to leave out leaders from the Kurdistan region of Iraq was called a “travesty” by Masrour Barzani, Chancellor of the Kurdistan Region Security Council. The Kurds have a “leading role” in the military campaign, Barzani pointed out. They’re expected to advance on Mosul from the north.

Carter, asked about Barzani’s concerns, said that the Kurds have done “spectacularly well” in fighting the Islamic State, and that he met with both the Kurdish Regional President Masoud Barzani and Iraqi Prime Minister Haider al-Abadi when he was in Baghdad recently.

“I’ve spoken to both of them on many occasions, to make sure that we’re all on the same page in the campaign so they know and Kurdish forces know that they’re an essential part of the campaign,” Carter said. “I’ve made this promise to Prime Minister Abadi and to President Barzani that I would make sure that our communications about the progress of the campaign between them was seamless, and that it would be conducted in the way that the Iraqi government under Prime Minister Abadi is conducting itself.”

The defense ministers gathered at Andrews in the morning before breaking off into smaller meetings. Carter said at the outset that the ministers would identify “enduring and emerging requirements” for the military campaign, without detailing what new steps or commitments may be needed. He called the stabilization effort a “critical and significant strategic priority.”

The debate has accelerated following the seizure of a key airfield 40 miles south of Mosul by Iraqi forces earlier this month. Carter announced shortly afterward on July 11 that he will send another 560 U.S. troops into Iraq, primarily to build up the airfield and make it usable again as a logistics and aviation hub to take back Mosul.

British Defense Secretary Michael Fallon told reporters Wednesday at Andrews that all countries in the coalition are being asked to do more, especially as the military campaign near Mosul intensifies.

“It’s very complex city with different faiths represented, and it’s all the more important… that the liberation has the support of the local population,” Fallon said. “A lot of planning has to be done to make sure that as the brigades go in and push their way into Mosul, the population is going to welcome them and support them.”